Amgen Says Trial Shows Drug Improved Bone Density

By ANDREW POLLACK

Published: October 4, 2004

Amgen said yesterday that its experimental drug for osteoporosis increased bone density in women at least as well in a clinical trial as the widely prescribed Fosamax medicine from Merck.

The drug in development, known as AMG 162, is considered by many analysts to be Amgen's best hope for a hit product, so the results of the trial are expected to be scrutinized by investors as well as doctors. The share price of Amgen, a leading biotechnology company, has declined 11 percent in the last year, in part because investors are concerned that it will not have enough new products to sustain its rapid growth.

While Amgen called the research results encouraging, they are from a Phase II trial, the middle stage of testing. The company has begun a final-stage trial that will test whether the drug prevents fractures, a more meaningful gauge than whether it increases bone mineral density. That trial could take two or three years.

The latest trial involved 411 postmenopausal women who received either one of several doses of AMG 162, Fosamax or a placebo.

AMG 162 increased bone mineral density in the spine and hip by a statistically significant amount after a year compared with the patients' starting condition and with the placebo, according to a company statement and Dr. Michael R. McClung, the principal investigator and founding director of the Oregon Osteoporosis Center in Portland.

In most cases, AMG 162 increased bone density about as much as Fosamax, Dr. McClung, who is also an associate professor at Oregon Health and Science University, said in an interview. But at the dose of AMG 162 that Amgen plans to use in the future, the drug increased density in the hip significantly more than Fosamax.

''This is not a study that proves that AMG 162 will be more effective than Fosamax,'' said Dr. McClung, who presented the results yesterday at the annual meeting of the American Society for Bone and Mineral Research in Seattle. ''But we wanted to see responses that were at least as good and in the same range as Fosamax.'' He also said that AMG 162 began to work in days while Fosamax took weeks.

Fosamax, which had sales of $2.7 billion last year, is the most widely prescribed drug treatment for bone thinning. But it and others in a class of drugs called bisphosphonates, like Actonel from Procter & Gamble and Sanofi-Aventis, can irritate the esophagus, causing symptoms of heartburn. And the pills, usually taken once a week, are supposed to be swallowed first thing in the morning, with the patient remaining upright and not eating or drinking for at least 30 minutes afterward.

AMG 162, which works through a new mechanism discovered by Amgen, would be given by injection once every six months.

In the trial, the side effects of AMG 162 did not differ from those of the placebo, the company said.